Using "-device virtio-gpu,blob=true" currently does not work on big
endian hosts (like s390x). The guest kernel prints an error message
like:
[drm:virtio_gpu_dequeue_ctrl_func [virtio_gpu]] *ERROR* response 0x1200 (command 0x10c)
and the display stays black. When running QEMU with "-d guest_errors",
it shows an error message like this:
virtio_gpu_create_mapping_iov: nr_entries is too big (83886080 > 16384)
which indicates that this value has not been properly byte-swapped.
And indeed, the virtio_gpu_create_blob_bswap() function (that should
swap the fields in the related structure) fails to swap some of the
entries. After correctly swapping all missing values here, too, the
virtio-gpu device is now also working with blob=true on s390x hosts.
Fixes: e0933d91b1 ("virtio-gpu: Add virtio_gpu_resource_create_blob")
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2230469
Message-Id: <20230815122007.928049-1-thuth@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
d194362910